1. Field of the Invention
This invention relates generally to transducer suspension systems and more particularly to a wiring system for a low profile transducer suspension.
2. Description of the Prior Art
Direct access storage devices (DASD), or disk drives, store information on concentric tracks of rotatable magnetic recording disks. A magnetic head or transducer element is moved from track to track to record and read the desired information. Typically, the magnetic head is positioned on an air bearing slider which flies above the surface of the rotating disk. In some recently proposed disk drives, the slider rides on a liquid film or bearing on the disk. A suspension assembly connects the slider to a rotary or linear actuator. The suspension provides support for the slider.
Examples of transducer suspensions are given in the following references: U.S. Pat. No. 3,665,434, issued May 23, 1972, to Applequist et al; U.S. Pat. No. 5,074,029, issued Dec. 24, 1991, to Brooks Jr. et al; U.S. Pat. No. 5,249,092, issued Sep. 28, 1993, to Russell-Smith et al; U.S. Pat. No. 5,282,103, issued Jan. 25, 1994, to Hatch et al; U.S. Pat. No. 5,327,310, issued Jul. 5, 1994, to Bischoff et al; U.S. Pat. No. 5,331,489, issued Jul. 19, 1994, to Johnson et al; U.S. Pat. No. 5,353,181, issued Oct. 4, 1994, to Frater et al; U.S. Pat. No. 5,392,179, issued Feb. 21, 1995, to Sendoda; Japanese Patent Application 2-270872, published Oct. 8, 1990, to Fuchigami; Japanese Patent Application 4-220548, published Aug. 20, 1992, to Otsuka; Japanese Patent Application 4-272635, published Oct. 12, 1992, to Kodaira; and IBM Technical Disclosure Bulletin Vol. 37, No. 8, Aug. 1994, page 427.
Electrical wiring must be run along the suspension from the electrical circuitry of the disk drive to the transducer element on the slider. One common way to do this is to run the wires in an insulating tube which is attached to the side of the suspension. At the end of the suspension, the wires exit the insolation tube and are electrically connected to the transducer pads on the slider. A problem with this design is that it requires that the wiring be manually assembled. This is very time consuming and requires a significant amount of labor cost.
Another method to assembling the wire for a suspension is shown in U.S. Pat. No. 5,074,029. This patent teaches a method for automated wire stringing of the wires along the suspension.
Electrical wires are strung along the top of the suspension and are bent around the end of the suspension for attachment to the transducer element located on the side of the slider. One problem has been that this bend causes the wire height at that location to increase. In disk drives having multiple disks, there is a limited amount of space between the disks and any increase in wire height is undesirable. Also, small disk drives having a single disk, such as PCMCIA drives also have limited amounts of height and additional space taken up by suspension wiring is undesirable.
One method used to solve this problem is to run a member along the wiring in a direction parallel to the longitudinal direction of the wires. This presses the wires down and forward along the suspension so that they bunch up at the end of the suspension at a location over the slider. Although the height of the wiring is somewhat reduced, the bunching of the wires at the end still causes the wires to have a significant height. In addition, the bunching also causes large stresses to be concentrated at the wire bonding sights. These stresses can cause the wires to detach from their electrical connections, thus causing the disk drive to fail.
In both the manual and automated wire stringing processes, the wires must be bent at the end of the suspension in order to attach to the slider below. This causes the wire height to increase at that location. The increase in wire height is undesirable.
What is needed, is a suspension design and method of assembly which reduces the wire height on the suspension and does not impart large stresses to the electrical connection and also allows the slider gimbal the freedom to move.